The present invention relates to a device for the wet treating of seed material, such as grains, comprising a substantially rotation-symmetrical treating chamber including an annular bottom wall sloping towards a central discharge opening thereof, an upper wall concentrically arranged above the bottom wall and sloping towards the periphery of the latter, the rim of the upper wall being spaced apart from the periphery of the bottom wall to form therewith an annular gap for passing the seed material into the treating chamber spraying means arranged in the treating chamber and being connected to a source of treating liquid; seed feeding means having an outlet opening arranged concentrically above said upper wall to feed the seed material onto the latter; and dosing means being slidably supported for limited coaxial displacement relative to the outlet opening of said seed feeding means.
British Pat. No. 972 854 discloses a device of this kind especially suited for cotton seed in which the seed material is positively fed by an auger conveyor from a hopper through a discharge opening from which the seeds are fed on the upper wall of the treating chamber. The flow of the cotton seed is regulated manually by displacing a slide collar surrounding the lower outlet end of said hopper. The cotton seeds are distributed on the upper wall of the treating chamber and thereafter slide down on the botteom wall thereof to the central discharge opening while being sprinkled with the treating agent.
The quantity of the treating agent applied to a certain quantity of seed material is restricted by law to be within certain narrow weight limits. The treating agent must be applied on the grains of the seed material from all sides and as uniformly as possible. The flow regulating slide collar of the known device cannot provide a sufficiently constant flow rate of the seed material so that considerable fluctuations of the weight ratio between the seed and the treating agent will occur. Moreover, the known device is not suited for small seeds and does not permit an exact preadjustment of flow rates for different kinds of seeds and different throughputs. Due to the predominantly sliding movement of the seed material on the bottom wall of the treating chambere, the grains are sprinkled with the treating agent in a non-uniform manner and frequently are wetted on one side only.